The present invention relates to a device for use in connecting electronic and other user devices. More particularly, the present invention relates to compact and versatile extension arms on which electronic devices such as flat panel displays, keyboards, etc. can be mounted.
In the past people have placed video monitors and other electronic equipment on desks, tabletops, or upon other equipment such as personal computers or workstations. One drawback to these configurations is the reduction in available workspace taken up by the equipment. Another drawback is the inability to place the equipment in a desired location. A further drawback is the potential for eye strain, neck strain and/or a cumulative trauma disorder such as carpel tunnel syndrome from poor placement of devices such as monitors and keyboards.
Different solutions have been provided in order to overcome these obstacles. For example, in one solution, a monitor stand or printer stand elevates the apparatus over other equipment on a desk. While this may free up workspace, it often places the equipment in an undesirable location. Another solution employs a mechanical extension arm to support the monitor. Extension arms free up workspace and allow users to place the equipment where it is wanted. One such extension arm is shown and described in U.S. Pat. No. 6,478,274, entitled “Arm Apparatus for Mounting Electronic Devices,” which is fully incorporated by reference herein. Another type of extension arm is shown and described in U.S. Pat. No. 6,409,134, entitled “Arm Apparatus For Mounting Electronic Devices With Cable Management System,” which is fully incorporated by reference herein.
It is often desirable to obtain additional freedom of movement beyond that provided by the extension arm. A tilting device can be used to accomplish this goal. The tilting device is placed between the extension arm and the equipment, allowing the equipment to rotate about one or more axes. One such tilting device is shown and described in U.S. Pat. No. 6,505,988, entitled “Tilter for Positioning Electronic Devices,” which is fully incorporated by reference herein.
FIGS. 1-7 illustrate a known extension arm 10 for mounting an electronic device. As shown in FIG. 1, the main elements of the extension arm 10 are a first endcap 12, an upper channel 14, a lower channel 16, a second endcap 18, and a forearm extension 20. The first endcap 12 has an endcap shaft 22 that is pivotably attachable to a rigid support mount (not shown), such as an orifice sized to accept the endcap shaft 22 or a track configured and sized to engage the grooves on endcap shaft 22. The shaft 22 is rotatable about an axis 24. The first endcap 12 is pivotably coupled via pins 26 to both the upper channel 14 and the lower channel 16. The pins 26 extend through receptacles in the upper and lower channels and span the width of the first endcap 12. As seen in the figure, the pins 26 are vertically aligned along a line 28 that is parallel to the axis 24. The opposite ends of the upper channel 14 and the lower channel 16 are pivotably coupled via pins 26′ to the second endcap 18. The forearm extension 20 is pivotably coupled to the second endcap 18 by the endcap shaft 22′, which may be a hollow tubular member fixedly attached to the second endcap 18. The forearm extension 20 has a vertically disposed hole 30 therethrough for accepting a shaft 32 of a mounting device (not shown) such as a tilter, platform or other apparatus. The forearm extension 20 includes a hollow interior 34 so that a cable 36 of the mounted device can pass through the forearm extension 20. The cable 36 can extend through a hollow tubular member of the second endcap 18. The cable 36 can pass through a sheath or cover 38 attached to the lower channel 16. The hollow interior 34 and/or the sheath 38 hide the cable 36 from view.
The combination of the upper and the lower channels 14, 16 and the first and the second endcaps 12, 18 form an adjustable parallelogram that permits a device coupled to the forearm extension 20 to be raised and lowered to a desirable height. The parallelogram retains its position by employing an extension/retraction device such as a gas spring 40, which is pivotably and adjustably attached to the first endcap 12 and the upper channel 14, as will be further described below. Generally, the gas spring 40, e.g., a gas type hydraulic cylinder and a retractable piston rod, is sized so as to have a fixed length until an upward or downward force is exerted at the second endcap 18 that exceeds the gas spring's designed resistance. Thus, the gas spring 40 causes the parallelogram to retain its position when the only force exerted at the second endcap 18 is the weight of the device, but permits the parallelogram to be adjusted when a user pushes the device coupled to the forearm extension 20 up or down.
FIG. 2 illustrates a side view of the first endcap 12, having the endcap shaft 22 disposed on a first end 42 of the first endcap 12. To provide a rigid connection between the two pieces, the endcap shaft 22 is typically machined from steel and is inserted into the first end 42 during the casting process of the first endcap 12. The endcap shaft 22 has a hole 44 formed in an end of the endcap shaft 22 that is inserted into the first endcap 12. The first endcap 12 is typically fabricated from cast aluminum. The first endcap 12 also has a second end 46 having a hole 48 disposed therethrough. Disposed within the first endcap 12 is a threaded rod 50. A first end 52 of the threaded rod 50 is inserted into the hole 44 at the base of the endcap shaft 22. A second end 54 of the threaded rod 50 is aligned with the hole 48 and is held in place by a clip 56. The clip 56 is fastened to an inner surface of the first endcap 12 by screws 58. The threaded rod 50 is parallel to the line 28 and is typically aligned along the axis 24.
Threadedly mounted on the threaded rod 50 is a clevis 60. FIG. 3 illustrates a side view of the clevis 60 including a tapped hole 62 in the center thereof. The tapped hole 62 receives the threaded rod 50, as shown in FIG. 2. At a first end of the clevis 60 is a pair of fastening members 64, 66 to which is fastened one end of the gas spring 40. A second end 68 of the clevis 60 is configured to slideably engage a track 70 which is integrally molded in the first endcap 12 (see FIG. 2). The second end 54 of the threaded rod 50 is configured to be engaged by a hex-shaped key, which is inserted through the hole 48 when the second end 54 is properly aligned with the hole 48. The hex-shaped key is employed so as to rotate the threaded rod 50 along its axis of rotation. When the threaded rod 50 is rotated along its axis of rotation, the clevis 60 moves along the length of the threaded rod 50 in a direction that corresponds to the direction which the hex-shaped key is turned. This movement of the clevis 60 permits the gas spring 40 to be adjusted. Specifically, the clevis 60 moves up or down along the track 70 in a path parallel to the line 28.
FIGS. 4A and 4B illustrate the upper channel 14, which comprises channel bottom 72 from which extend two channel sidewalls 74. Channel bottom 72 and sidewalls 74 are typically stamped from 13 gauge steel sheet in order to give the upper channel 14 a desired degree of structural rigidity. At each of the ends of the channel bottom 72, a semi-circular region 76 of the sidewalls 74 is cut out to accommodate cold-rolled steel rollers 78, which have a hole 79 therethrough for receiving the pins 26 or 26′. The rollers 78 are rigidly attached to the upper channel 14 by MIG welding along the edge of the semi-circular cut out region 76 and along the ends of the channel bottom 72. Alternatively, the rollers 78 are integrally cast with the exterior of the upper channel 14 during fabrication.
Additionally, the upper channel 14 comprises stiffener 80, which is welded to an inner surface of the channel bottom 72. Besides providing additional structural rigidity to the upper channel 14, the stiffener 80 has a hole disposed at one end with a threaded ball stud 82 placed within the hole and fixed in place by a nut 84. The ball stud 82 is configured and sized to receive one end of the gas spring 40. The longitudinal centerline 85 of the upper channel 14 is illustrated in FIG. 4B. FIGS. 4C and 4D illustrate an alternative upper channel 14′. The upper channel 14′ is constructed to optionally include internal reinforcements. This is particularly advantageous when mounting heavy electronic devices to the extension arm, for example, large computer monitors of the CRT type. Internal within the upper channel 14′ is a rib assembly including a plurality of cross-ribs 86 and angularly disposed secondary ribs 87. By way of example, the cross-ribs 86 are disposed transverse to the sidewalls 74, while the secondary ribs 87 are disposed at an angle so as to form a triangular internal support structure. The cross-ribs 86 and secondary ribs 87 may be formed as an integral member which can be inserted into the upper channel 14′. The cross-ribs 86 and secondary ribs 87 can be integrally cast during formation of the upper channel 14′.
FIGS. 5A and 5B illustrate the lower channel 16, which comprises a channel bottom 88 from which extend two channel sidewalls 90. As with the upper channel 14, the channel bottom 88 and sidewalls 90 are typically stamped from 13 gauge steel sheet, which is relatively heavy in order to give the lower channel 16 a desired degree of structural rigidity. At opposite ends of the channel bottom 88, a semi-circular region 91 of the sidewalls 90 is cut out to accommodate cold-rolled steel rollers 92, which have a hole 93 therethrough for receiving the pins 26 or 26′. The rollers 92 are rigidly attached to the lower channel 16 by MIG welding along the edge of the semi-circular cut out region 91 and along the ends of the channel bottom 88. Alternatively, the rollers 92 are integrally cast with the exterior of the lower channel 16 during fabrication. The longitudinal centerline 94 of the lower channel 16 is illustrated on FIG. 5B.
FIG. 6 illustrates a variant of the second endcap 18 of FIG. 1. Unlike the first endcap 12, the second endcap 18 does not have a clevis assembly for attachment to the gas spring 40. The alternative second endcap 18 shown in FIG. 6 omits the endcap shaft 22′ for receiving the forearm extension 20, as illustrated in FIG. 1. Instead, the endcap 18 may include hole 95 at one end for receiving a shaft of the forearm extension 20. The endcap 18 may also include hole 96 for receiving a set screw (not shown) to prevent rotation of the forearm extension 20 about the endcap 18.
FIG. 7A illustrates the forearm extension 20 having a central arm 31 and first and second ends 33, 35, respectively, attached to the central arm 31. The first end 33 includes an opening 37 for connection with the endcap shaft 22′ of the second endcap 18. The second end 35 includes the opening 30 for receiving the shaft of the device mount. An opening 39 is provided for access to the interior 34. As seen in the cutaway view of FIG. 7B along the A-A line, there is access to the opening 37 of the first end 33 via region 41, which allows the cable 36 to be hidden from view.
Known extension arms, such as those in FIGS. 1-7, may operate satisfactorily, but may not be well suited for sleeker, more compact designs. Reducing the size of some components can, if not correctly engineered, adversely impact equipment performance. By was of example only, an extension arm may be made smaller by reducing the dimensions of the upper and lower channels. Such a modification would necessitate reducing size of the gas spring. Unfortunately, if the overall structure of the extension arm remains the same as the size is reduced, a smaller gas spring typically cannot handle the load of a large device, and, in turn, cannot support larger monitors or other equipment. In addition, some of the connection between components, such as the connection between the forearm extension 20 and the second endcap 18, can become loose, for example after repeatedly adjusting or rotating the forearm extension 20. Loose connections could potentially lead to hazardous conditions. Therefore, a need exists for new extension arm designs to address these and other concerns.